Cooling assembly

ABSTRACT

A cooling assembly includes a device chamber, a cooling chamber separated from the device chamber, a heat exchanger, a device chamber fan arrangement and a control unit. The heat exchanger includes a first portion located in the device chamber and a second portion located in the cooling chamber for transferring heat from the device chamber to the cooling chamber. The device chamber fan arrangement is configured to generate a device chamber cooling medium flow including a first partial flow interacting with the first portion of the heat exchanger. The cooling assembly also includes a first throttle arrangement for regulating the first partial flow. The control unit is configured to reduce a cooling power of the heat exchanger as a response to predetermined operating conditions by decreasing the first partial flow with the first throttle arrangement.

RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 to European PatentApplication No. 13153787.0 filed in Europe on February 4, 2013, theentire content of which is hereby incorporated by reference in itsentirety.

FIELD

The present disclosure relates to a cooling assembly including a heatexchanger for transferring heat from a device chamber.

BACKGROUND INFORMATION

Humidity is harmful to many electronic components. Humidity is an issue,for example, in solar power plants and wind power plants. Challengingenvironments such as tropical or arctic climates increase problemscaused by humidity.

In a known cooling assembly, heating of a device chamber is used toprevent excessive humidity. It is also known to use water absorbingmaterials such as silica gel to remove humidity from a device chamber.

Preventing humidity by means of heating induces extra cost. Waterabsorbing materials are also expensive and their useful life is limitedthereby further increasing cost.

SUMMARY

An exemplary embodiment of the present disclosure provides a coolingassembly which includes a device chamber, a cooling chamber separatedfrom the device chamber, a heat exchanger, device chamber fan means, andcontrol means. The heat exchanger includes a first portion located inthe device chamber and a second portion located in the cooling chamberfor transferring heat from the device chamber to the cooling chamber.The device chamber fan means are configured to generate a device chambercooling medium flow including a first partial flow interacting with thefirst portion of the heat exchanger. The exemplary cooling assembly alsoincludes first throttle means for regulating the first partial flow. Thecontrol means are configured to reduce a cooling power of the heatexchanger as a response to predetermined operating conditions bydecreasing the first partial flow with the first throttle means.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional refinements, advantages and features of the presentdisclosure are described in more detail below with reference toexemplary embodiments illustrated in the drawings, in which:

FIG. 1 shows a cooling assembly according to an exemplary embodiment ofthe present disclosure;

FIG. 2 shows a cooling assembly according to an exemplary embodiment ofthe present disclosure; and

FIG. 3 shows a cooling assembly according to an exemplary embodiment ofthe present disclosure.

DETAILED DESCRIPTION

Exemplary embodiments of the present disclosure provide a coolingassembly which is capable of alleviating disadvantages caused byhumidity.

Exemplary embodiments of the present disclosure are based on the idea ofdecreasing in predetermined operating conditions a relative humiditylevel in a device chamber by reducing a cooling power of a heatexchanger configured to transfer heat from the device chamber. Thecooling power is reduced by a first throttle means capable of regulatinga first partial flow of a cooling medium interacting with a firstportion of the heat exchanger located in the device chamber. Exemplaryembodiments of the present disclosure improve controllability of a heatexchanger by lowering a minimum cooling power of the heat exchanger.Decreasing cooling power of the heat exchanger raises the temperature ina device chamber thereby reducing relative humidity.

An advantage of the cooling assembly of the present disclosure is that arelative humidity level inside a device chamber can be decreased with avery small operating cost.

FIG. 1 shows a cooling assembly including a device chamber 2, a coolingchamber 4, a heat exchanger 3, device chamber fan means, control means 6(e.g., a computer processor configured to execute a computer programand/or computer-readable instructions tangibly recorded on anon-transitory computer-readable recording medium, such as anon-volatile memory), a humidity sensor 61, a temperature sensor 62,first throttle means 81, and an electrical apparatus 102. The coolingchamber 4 is separated from the device chamber 2. The heat exchanger 3includes a first portion 31 located in the device chamber 2 and a secondportion 32 located in the cooling chamber 4 for transferring heat fromthe device chamber 2 to the cooling chamber 4. The first portion 31 ofthe heat exchanger is in an operating situation located lower than thesecond portion 32 of the heat exchanger.

The device chamber fan means are configured to generate a device chambercooling medium flow including a first partial flow interacting with thefirst portion 31 of the heat exchanger 3. As used herein, interactionbetween a cooling medium flow and a heat exchanger means heat transferbetween the cooling medium flow and the heat exchanger. The firstthrottle means 81 are configured for regulating the first partial flow.The humidity sensor 61 is configured to detect a humidity level in thedevice chamber 2. The temperature sensor 62 is configured to detect atemperature in the device chamber 2.

The control means 6 are configured to reduce a cooling power of the heatexchanger 3 as a response to predetermined operating conditions bydecreasing the first partial flow with the first throttle means 81. Thefirst throttle means 81 are configured to regulate the first partialflow by adjusting a bypass flow of the cooling medium. The bypass flowis a portion of the device chamber cooling medium flow that bypasses thefirst portion 31 of the heat exchanger 3 without interaction. Thepredetermined operating conditions including a situation where thehumidity sensor 61 detects a humidity level exceeding a predeterminedthreshold value in the device chamber 2, and a situation where thetemperature sensor 62 detects a temperature below a predeterminedthreshold value in the device chamber 2. In accordance with an exemplaryembodiment, a predetermined condition is defined as a function ofhumidity and temperature.

A wall 22 separates a first flow channel 71 from a second flow channel72. The first portion 31 of the heat exchanger 3 is located in the firstflow channel 71. The second flow channel 72 extends between theelectrical apparatus 102 and the wall 22 bypassing the first portion 31of the heat exchanger 3. There is an opening 24 in the wall 22 providinga passage between the first flow channel 71 and the second flow channel72. According to an exemplary embodiment, the first throttle means 81include a generally planar first valve plate 812 configured to pivotabout a pivoting axis extending substantially parallel to a planedefined by the first valve plate 812. The pivoting axis passes through alower edge of the first valve plate 812. The first valve plate 812 has aclosed position and an open position. In the closed position, the firstvalve plate 812 closes the opening 24 in the wall 22. In FIG. 1, theclosed position of the first valve plate 812 is depicted with a dashedline. In the open position, the first valve plate 812 allows a bypassflow of the cooling medium from the first flow channel 71 to the secondflow channel 72 through the opening 24. In FIG. 1, the first valve plate812 is in the open position.

In accordance with an exemplary embodiment, the first valve plate 812only has two positions, the open position and the closed position. Inother exemplary embodiments, the first throttle means may have more thantwo positions including at least one intermediate position between anopen position and a closed position. Alternatively, the control meansmay be configured to alternate the position of the first throttle meansbetween an open position and a closed position in order to provide anaverage bypass flow of the cooling medium smaller than the bypass flowcorresponding to the open position of the first throttle means.

According to an exemplary embodiment, the heat exchanger 3 is a cothextype heat exchanger. A cothex is a thermosyphon heat exchanger where acooling medium circulates by means of natural convection without amechanical pump. In another exemplary embodiment, a heat exchangerconfigured to transfer heat from the device chamber to the coolingchamber may include another type of passive heat exchanger, or an activeheat exchanger.

The electrical apparatus 102 is provided with apparatus cooling fanmeans 51 (e.g., at least one fan) located inside a housing of theelectrical apparatus 102 and configured for cooling the electricalapparatus 102. In the embodiment of FIG. 1, the device chamber fan meansincludes the apparatus cooling fan means 51.

One skilled in the art understands that relative humidity in the devicechamber 2 could be slightly decreased by reducing power of apparatuscooling fan means 51. However, reducing a power of the apparatus coolingfan means 51 could lead to unfavourable heat distribution inside theelectrical apparatus 102. Further, reducing a power of apparatus coolingfan means 51 could in fact increase relative humidity in some parts ofthe device chamber 2.

In another exemplary embodiment, the device chamber fan means caninclude at least one fan not belonging to the apparatus cooling fanmeans but specifically configured to generate a device chamber coolingmedium flow. Such at least one fan may be located separately from theelectrical apparatus.

In accordance with an exemplary embodiment, the electrical apparatus 102includes a frequency converter. In another exemplary embodiment, anelectrical apparatus located in the device chamber may include aninverter or some other heat generating apparatus that requires cooling.

In the exemplary embodiment of FIG. 1, the device chamber cooling mediumflow always includes some bypass flow of the cooling medium irrespectiveof operation of the first throttle means 81. In the closed position ofthe first valve plate 812, a bypass flow passes through the second flowchannel 72 and a third flow channel 73 extending between the electricalapparatus 102 and an inner wall of the device chamber 2.

In accordance with another exemplary embodiment, a closed position offirst throttle means substantially prevents a bypass flow of the coolingmedium. The bypass flow is a portion of the device chamber coolingmedium flow that bypasses the first portion of the heat exchangerwithout interaction. For example, blocking the second flow channel 72and the third flow channel 73 in the cooling assembly of FIG. 1 wouldprovide such an embodiment.

The cooling assembly further includes second throttle means 82 andcooling chamber fan means 52 (e.g., at least one fan and/or aventilation arrangement) for regulating a cooling chamber cooling mediumflow interacting with the second portion 32 of the heat exchanger 3. Thecontrol means 6 are configured to reduce a cooling power of the heatexchanger 3 as a response to predetermined operating conditions bydecreasing the cooling chamber cooling medium flow by controlling thesecond throttle means 82 and the cooling chamber fan means 52.

The device chamber 2 is separated from the cooling chamber 4 such thatthere is substantially no cooling medium flow between the device chamber2 and the cooling chamber 4. Therefore, substantially no contaminantparticles can pass from the cooling chamber 4 into the device chamber 2.According to an exemplary embodiment, the cooling medium in the coolingchamber 4 as well as in the device chamber 2 is air.

A wall 42 separates a first portion 401 of the cooling chamber 4 from asecond portion 402 of the cooling chamber 4. The first portion 401 ofthe cooling chamber 4 includes the second portion 32 of the heatexchanger 3. The second portion 402 of the cooling chamber 4 includesthe cooling chamber fan means 52. The second portion 402 is in anoperating situation located above the first portion 401. There is anopening 44 in the wall 42 providing a passage between the first portion401 of the cooling chamber 4 and the second portion 402 of the coolingchamber 4.

According to an exemplary embodiment, the second throttle means 82include a generally planar second valve plate 822 configured to pivotabout a pivoting axis extending substantially parallel to a planedefined by the second valve plate 822. The pivoting axis passes throughan upper edge of the second valve plate 822. The second valve plate 822has a closed position and an open position. In the closed position, thesecond valve plate 822 closes the opening 44 in the wall 42. In FIG. 1,the closed position of the second valve plate 822 is depicted with adashed line. In the open position depicted in FIG. 1, the second valveplate 822 allows a flow of cooling medium from the first portion 401 ofthe cooling chamber 4 to the second portion 402 of the cooling chamber 4through the opening 44. The open position of the second valve plate 822increases a cooling power of the heat exchanger 3 compared to the closedposition of the second valve plate 822, because a lower part of thefirst portion 401 of the cooling chamber 4 and the second portion 402 ofthe cooling chamber 4 include openings allowing the cooling medium toflow between exterior of the cooling assembly and the cooling chamber 4.Consequently, the open position of the second valve plate 822 induces adraught in the cooling chamber 4 during operation of the coolingassembly.

When the control means 6 detect an operating condition that requires orallows reducing cooling power of the heat exchanger 3, the control means6 turns off the cooling chamber fan means 52. If the turning off of thecooling chamber fan means 52 does not reduce a cooling power of the heatexchanger 3 enough the control means 6 opens the first valve plate 812and/or closes the second valve plate 822.

In the embodiment of FIG. 1, the first throttle means 81 include onlyone valve member, namely the first valve plate 812. In another exemplaryembodiment, first throttle means may include a plurality of valvemembers. For example, FIG. 2 shows a cooling assembly in which firstthrottle means 81′ include a first adjustable grill 816′ and a secondadjustable grill 836′. The first adjustable grill 816′ includes aplurality of louvers 861′, and the second adjustable grill 836′ includesa plurality of louvers 862′.

The first adjustable grill 816′ is located in an opening 24′ in a wall22′, and is configured to regulate a cooling medium flow through theopening 24′. The second adjustable grill 836′ is located adjacent to anupper surface of the first portion 31′ of the heat exchanger 3′. Thecontrol means 6′ are configured to control both the first adjustablegrill 816′ and the second adjustable grill 836′. A first partial flowinteracting with the first portion 31′ of the heat exchanger 3′ isminimized by an open position of the first adjustable grill 816′ and aclosed position of the second adjustable grill 836′. The first partialflow is maximized by a closed position of the first adjustable grill816′ and an open position of the second adjustable grill 836′.

The control means 6′ are configured to steplessly control the firstadjustable grill 816′ and the second adjustable grill 836′. In FIG. 2,both the first adjustable grill 816′ and the second adjustable grill836′ are in an intermediate position between an open and closedposition.

A type of valve member of the first throttle means and second throttlemeans is not limited to a planar valve plate and an adjustable grill.FIG. 3 shows a cooling assembly in which first throttle means 81″include a cylindrical valve 814″ whose valve surface has a general formof a cylindrical segment. The valve surface of the cylindrical valve814″ is configured to pivot about a pivoting axis extendingsubstantially parallel to an axis of the cylindrical segment. Thecontrol means 6″ are configured to steplessly control the cylindricalvalve 814″.

It should be noticed that although both second throttle means 82′ ofFIG. 2 and second throttle means 82″ of FIG. 3 include a generallyplanar second valve plate, the second throttle means may alternativelyinclude an adjustable grill, a cylindrical valve, or any other suitablevalve member.

Except for the first throttle means, the cooling assemblies of FIGS. 1to 3 are quite similar. The only further significant difference relatesto a wall separating a first flow channel from a second flow channel.For example, in the cooling assembly of FIG. 3, the segments of wall 22″located adjacent the cylindrical valve 814″ are inclined towards thecylindrical valve 814″ in order to better co-operate with it. The wallsegments have been inclined because of a relatively long radius of thecylindrical valve 814″ and a relatively short distance between a wall22″ and an electrical apparatus 102″.

In accordance with an exemplary embodiment, a cooling assembly includesheating means (e.g., a heater) for heating the device chamber. In thisembodiment, the control means are configured to decrease the firstpartial flow with the first throttle means when the heating means are inuse. Such operation improves efficiency of the heating by reducing heatloss from the device chamber.

It will be appreciated by those skilled in the art that the presentinvention can be embodied in other specific forms without departing fromthe spirit or essential characteristics thereof. The presently disclosedembodiments are therefore considered in all respects to be illustrativeand not restricted. The scope of the invention is indicated by theappended claims rather than the foregoing description and all changesthat come within the meaning and range and equivalence thereof areintended to be embraced therein.

What is claimed is:
 1. A cooling assembly comprising: a device chamber; a cooling chamber separated from the device chamber; a heat exchanger; device chamber fan means; and control means, wherein: the heat exchanger comprises a first portion located in the device chamber and a second portion located in the cooling chamber for transferring heat from the device chamber to the cooling chamber; the device chamber fan means are configured to generate a device chamber cooling medium flow including a first partial flow interacting with the first portion of the heat exchanger; the cooling assembly comprises first throttle means for regulating the first partial flow; the control means are configured to reduce a cooling power of the heat exchanger as a response to predetermined operating conditions by decreasing the first partial flow with the first throttle means.
 2. A cooling assembly according to claim 1, wherein the cooling assembly comprises a humidity sensor configured to detect a humidity level in the device chamber, and wherein the predetermined operating conditions comprise a situation where the humidity sensor detects a humidity level exceeding a predetermined threshold value in the device chamber.
 3. A cooling assembly according to claim 2, wherein the cooling assembly comprises a temperature sensor configured to detect a temperature in the device chamber, and wherein the predetermined operating conditions comprise a situation where the temperature sensor detects a temperature below a predetermined threshold value in the device chamber.
 4. A cooling assembly according to claim 1, wherein the cooling assembly comprises a temperature sensor configured to detect a temperature in the device chamber, and wherein the predetermined operating conditions comprise a situation where the temperature sensor detects a temperature below a predetermined threshold value in the device chamber.
 5. A cooling assembly according to claim 1, wherein the first throttle means are configured to regulate the first partial flow by adjusting a bypass flow of the cooling medium, the bypass flow being a portion of the device chamber cooling medium flow that bypasses the first portion of the heat exchanger without interaction.
 6. A cooling assembly according to claim 1, wherein the first throttle means comprise a generally planar first valve plate configured to pivot about a pivoting axis extending substantially parallel to a plane defined by the first valve plate.
 7. A cooling assembly according to claim 1, wherein the first throttle means comprise a cylindrical valve whose valve surface has a general form of a cylindrical segment, the valve surface being configured to pivot about a pivoting axis extending substantially parallel to an axis of the cylindrical segment.
 8. A cooling assembly according to claim 1, wherein the first throttle means comprise a first adjustable grill with a plurality of louvers.
 9. A cooling assembly according to claim 1, wherein the first portion of the heat exchanger is in an operating situation located lower than the second portion of the heat exchanger.
 10. A cooling assembly according to claim 9, wherein the heat exchanger comprises a passive heat exchanger.
 11. A cooling assembly according to claim 10, wherein the heat exchanger comprises a thermosyphon heat exchanger.
 12. A cooling assembly according to claim 1, comprising: second throttle means for regulating a cooling chamber cooling medium flow interacting with the second portion of the heat exchanger, wherein the control means are configured to reduce a cooling power of the heat exchanger as a response to predetermined operating conditions by decreasing the cooling chamber cooling medium flow with the second throttle means.
 13. A cooling assembly according to claim 1, comprising: an electrical apparatus in the device chamber, the electrical apparatus having apparatus cooling fan means configured for cooling the electrical apparatus, the apparatus cooling fan means constituting at least part of the device chamber fan means.
 14. A cooling assembly according to claim 13, wherein the device chamber fan means consists of the apparatus cooling fan means.
 15. A cooling assembly according to claim 13, wherein the electrical apparatus comprises one of a frequency converter and an inverter. 